One half or one second for fractions

[sadra1400]

Sorry guys, for my elementary question.
One half, one third, one fourth,...
Why do we not say one second instead of one half? Is that wrong?

 

[5jj]

Yes, one second is wrong.

One fourth is not wrong, but one/a quarter is more common.

 

[tedmc]

I think half is usually said without one, unlike one third and one quarter.

 

[Tdol]

The indefinite article is common with fractions- a half, a quarter, a fifth. It depends on the context whether we use half or a half/one half.

 

[SoothingDave]

It is legitimate to say "five thirty-seconds of an inch."

Thirty-seconds of an inch are used to measure tire tread depth in the US.

 

[Rover_KE]

Yes.

Why do we not say "one second" instead of "one half"?

One second is a measure of time – not length.